Fluid actuated valve



Feb. 3, 1942. v P. LOEWE FLUID ACTUATED'VALVE Filed NOV. 9, 1940 1 INVENI'OR.

Wm u w Patented Feb. 3; 1942 Logansport Machine; Incorporated Application November 9,1940; serial N0. 365;096

s'olailns; (cam -60y ,7

from "one' of the"compartmentsto theother'. illustrated," the bore also extends longitudinally My invention'relates in general to control valves and-more particularly to fluid actuated control valves adapted to control the flow of fluidin a fluid system having fluid operated-devices.

An object of my invention is the provision'of a fluid operated valve which is governed in'response I to a building up of pressure to a predetermined value.

Another object of my invention is the provision of a fluid operated valve which gives a prede termined and definite metering pressure.

Another object of my invention is the provision of preventing thevalve parts from chattering. 7

Another object of my invention is the provision of' a fluid valve which avoidsthe creation of a "vacuum therein by the movement ofthe'valve piston.

Another object of my mventionis the provision of a valve which'admits free return passageiof 1 Another object of my invention isthe provision.

of an automatic fluid valve to operate a plurality offluid devices in a fluid'system, in which one of into the'casingi'on opposite sides of the partition thefluid devices, for example, comprises a'holding-device for holding a workpiece and in which another" fluid device, for example, comprises a work" performing device, the arrangement being such that'the holding device isioperated first after which the work performing device is' operated. Another object of my invention is to avoidgin a fluid operated valve, large springs which are expensive and which produce inaccurate results.

Other objects and a; fuller understandingof my invention'may be had by referring to thelfollow ing description and claims, taken. in conjunction with the accompanying drawing, in which:

V Figure 1 is a longitudinalcross-sectional view of a valve embodying the features of my invention; I 1

Figure 2 isan end view of the valve shown in Figure 1; I e I Figure 3'is a view similar to'Figure" 1 except that-it shows thevalve parts in a different operatingposition, and

Figure4 is a diagrammaticviewpf a simple 1 control system "in which my valve finds useful application."

"I 3 and 'fo'rms'a first bore portion I! on theright p sideor the partition and asec'ond bore'portion-TB {onfthefleft side of the partition. The bore j is of the same";dir'nension or'diameter throughout' its entirei-leng-th. Slidably mounted in the first bore portion l1 and the bore IG'of-the partition is a main' valvepiston 24 which is arranged to regug late the flowof the fluid from one compartment tofthe other; A second piston 25 is slidably' *nidunted inthe' second boreportion I81 A rela-' tively light-spring ZB-is arranged to bias the main valve piston 24 to the left to its closed posi-tion" intothe bore lB-of-the partition as shown in' Figure-l; The movement of "the main valve piston-245th the left to its closed position is limited by the forward end of the valve contacting "the forward end of'the secondpiston '25. The

maini valve piston 24' and the second piston 25 "areg'rn'echanically free to move away from each -oth'er' as=they recede into their respective-bore portions. r The main-valve piston 24 and'the second piston 25 'are actuated to their right by a pressure respOnsive plunger 31 located in the rear or to the l'e'it'of the secondpiston'25. The pressure responsive plunger" 31- "is 'reciprocably mounted in a: longitudinal openingfl that extends from the left-hand end of'the second bore portion l8' over to an' extended portion or chamber-s5 of the first compartment l I through a core 36"shown by the dotted lines in Figure '1; In accordance with this .arran'gement the right-handend of thepressure responsive plunger '31 engages the left-hand or rear end of 'thesecond piston 25-a'n d the lefthand end of the pressure responsive plunger 31 is-exposed to the pressure whichbuilds up in the first compartment ,II and which extends over through the core 36 tojthe extended portion or 'chamber'35. The'screw'plug 40 in the left-hand end'of the casing lflis used to'fill up the hole v *Withreference to' the drawing, my valve'c'om madein the casing fwhen boring the longitudinal-opening 34: Upon the'building" up of pressure of a predetermined-value in the first compartment ll, thepressure-responsive plunger 31 actuates'the' second piston 25 "and the main'slide,

valve 'piston 2'4to the Tight: compressing the'com- I pression' spring 26: The adjustmentof the com-' 'pression of the-spring 26-may beset at a predewitli-*'a -bore-= I 6 and constitutes a valve-opening 5 terminedzvalue by operating: the spring adjustment threaded member 21. A- i am nut 28' may be provided to" prevent 1 the- 'spring adjustment member '21 "fromturning-when L once-"set; The

limit of movement of the main valve piston 24 to the right toward its open position is determined by a stop pin 29 engaging a stop adjustment screw 30. As shown, the stop pin 29 may be carried by the main valve piston 24 and is positioned internally of the spring 26. The stop adjustment screw 30 is threadably mounted within the spring adjustment member 21. When the adjustment of the stop adjustment screw 30 is once determined it may be secured in place by the jam nut 3|. The arrangement of the stop pin 29 and the adjustable stop adjustment screw 30 may be referred to as a metering adjustment to regulate the flow of the fluid from one compartment to the other. In the event that fluid leaks past the main valve piston 24 and past the second piston 25 and past the pressure responsive plunger 31, it may drain through a core 38 to a drain outlet 39.

As shown in Figure 1, a ball check valve H is positioned between the first compartment I I and the second compartment I2 of the valve casing. The ball of the ball check valve M is adapted to seat into a replaceable seat 42 having a. shoulder which rests upon a suitable packing 43 such, for example, as a Neoprene washer. A spring 44 mounted under a threaded cap 45 is arranged to constrain the ball against the replaceable seat 42. A gasket 46 may be positioned under the cap 45 to prevent fluid from seeping from the casing. The ball check valve 4I admits the free flowing of the fluid from the compartment I2 to the compartment II but restricts the flow of the fluid from the compartment II to the compartment I2.

The operation of my fluid control valve may be best understood by explaining its function in connection with a simple diagrammatic fluid system, shown in Figure 4, comprising a fluid holding cylinder 50, a fluid work performing cylinder a pump 53, a sump 54, a four-way fluid control valve 52 actuated by a, handle 55, and my control valve indicated by the reference character III. A piston 48 within the fluid holding cylinder 50 is arranged to operate a clamp or jaw 61 for holding a work piece 65 firmly against a stationary support 66, A piston 49 within the fluid work performing cylinder BI is arranged to move a work performing device 68 such, for example, as a drill within a support 69 relative to the work piece 65 by a bell crank I0. In the illustrated fluid system, my fluid valve I0 is arranged to cause the work 65 to be securely clamped in position before the work performing device 68 is brought in working engagement therewith. The delayed operation of my valve for bringing about the above described function may be explained as follows: Upon the actuation of the control handle 55 of the four-way valve to one position, fluid flows from the sump 54 through a pipe 59 to the pump 53, and then through the four-way valve and the pipes BI and 60 to the rod end of the fluid holding cylinder 50. The fluid actuates the clamp 61 downwardly and holds the work piece 65 against the stationary support 66. Fluid from the pipe 6I also flows through the pipe 62 into the first compartment II of my valve casing I0 where it is blanked oil from flowing into the second compartment by the main valve piston 24, until a predetermined build-up of pressure is obtained. The build-up of pressure in the fluid compartment I I is established upon the piston 48 of the fluid holding cylinder 50 meeting resistance as a clamp 61 presses against the work piece 65. Just as-soon as the .the sump 54.

j cylinder 5 I metering open position.

movement of the clamp 61 is arrested or just as soon as a definite amount of resistance is encountered by the piston 48, the pressure within the extended portion or chamber 35 of the first compartment II acting upon the left-hand end of the pressure responsive plunger 37 overcomes the force of the spring 26 and forces the second piston 25 and the main valve 24 to the right, until fluid can pass through the bore I6 of the partition I 3. The fluid upon flowing into the compartment I2 then passes through a pipe II to the rod end of the work performing cylinder 5|, whereupon the pressure within the fluid actuates the work tool 68 into working engagement with the work piece 65.

As the main valve piston 24 moves to the right it would tend to create a vacuum in the compartment I2 since this compartment is connected by fluid pipe connections to the cylinder 5I, but I overcome or avoid this vacuum by the simultaneous movement of the second piston 25 to the right. The chamber in the rear of the second piston 25 is connected by the core 38 to the drain outlet 39 and a pipe I2 to the sump 54, and thus as the second piston 25 moves to the right there is no vacuum created in the rear thereof since it is connected to atmosphere through the sump 54. Also, upon the main control valve piston moving to the right, a cushion would tend to be built up behind it, but this cushioning is relieved since the space in the rear of the main valve piston 24 is connected by the core 38 to the drain outlet 39 and thence to atmosphere through Therefore, the avoidance of the vacuum in the compartment I2 as well as the avoidance of the cushioning behind the main valve 24 gives smooth operation to my valve and prevents uneven operation or chattering thereof during its operating movement.

Upon the main control valve piston 24 being actuated to the right to its open position, fluid flows from the compartment II to the compartment I2 and thence to the rod end of the fluid In its open position, the forward or left-hand end of the main control valve piston 24 is exposed to the pressure in the compartment I2 and this pressure acting upon the large area of the forward or left-hand end of the main control valve piston 24 keeps the valve in its full The pressure in the compartment I2 also acts upon the large area of the second piston 25 and forces it, as well as the pressure responsive plunger 31, to the left. This position is shown in Figure 3 of the drawing. The rate of flow or the metering of the fluid through the valve opening depends upon the distance between the main control valve piston and the bore I6. This distance as explained before is regulated by the stop adjustment screw 30.

As the piston 48 within the fluid cylinder 50 and the piston 49 within the fluid cylinder 5I are moved downwardly, the fluids in the blind ends thereof are drained through the pipes 51 and 58, and the pipe 56, the fourway valve 52, and the pipe 13 to the sump 54. I Upon the actuation of the handle 35 of the four-way valve 52 to its neutral position, in which control valve piston to the left towards its closed position. .The main control valve piston, upon its movement to the left, displaces fluid within the compartment I2, which fluidis allowed to escape through the ball check valve 4I into the 2 27x091 V r valvecasingzhavinggatfirstand a seconacom artcompartment i 1 thus @balancing' thei entirea'flui'd system;

Upon.reversmgtheiouawig alveQSZFtIia-Huid flows from thenpur'np Ethroughathez fourewaycontrolwivalve andrthen through :pipes 56; 5I=Tiand 58 5 tothe blind ends of the vfl-uid icylinders' 50 land 5. l fitozoperate "the.-pistonszi l8iandi4 9i'simultaneously inuthe reverseor upwardidirection: Theifluid from 1 the: rodrend'" ofizthe =1 cylinder 50, upon' the 'upward'movement of r'the;pist'on't48, .flows through i' 10 the pipes filly-and 6-1;; and. the; four-way control valve 52' to the sump- The fiuid :in ;the :rod end of the fluid cylinder 5.I:-.upon+'the'supward movement oft e p ston dflaflowsisthrough the pipe :1 -l in' the compartmentl 2,;whereitmay free1y1fiowthrough the, .ball checksvalvej 14-1 ito :the compartment andjthencejthrough the pipesfs'62i and T61: to the foureway' control Zjvalve; '52; andl'. then jto the mpfi h;v r v .Therefore';-; I a provide an: automatic fluid :valve 1 which is useful mg-operating a= pluralityfof fluid devices; in a. fluid system; inwhich on'elof the V "fluid-devices, for example; comprises a liolding device for holding 'a;,workpiecei and: inv which another fiuididevice; fo'r'example, comprises a work performing device; the arrangement "being isuchthat thei'holdi'ng; device is operated. first after which I the]- work performing device is 0perated;

in the: details of construction and; the "combination and arrangement of partsmav bejresorted to without departing "from tnespirit and the scopeof th'e inventionkas hereinaiiterplaimed.

I olaimas myinvention: v '1; A'fluid'valve-comprising, in combination, a

valve casing having a first and a second 'com- 40 stituting a valve opemng from one of saidv compartments to the other, said bore also extending longitudinally into thecasing upon opposite sides of vthe partition andforming a first bore-portion partment separated by a partition, said partition having a bore passing therethrough andconstituting a valve opening from one of said com partments to the other, saidbore also extending longitudinally into'the casing upon opposite sides '45 of the partition and forming a first bore portion on the first compartment side of the partition and a second" bore portion on the second compartment side of the partition,- a slidable valve piston reciprocally mounted in the first bore portion and extending a'crossthe first com- 7 partment into the bore of the partition to regulate the flow of fluid from one compartment to the other, a second piston slidably mounted in the second bore portion, spring means for biasing the slidable valve piston-toward'its closed position into the bore of the partition against the I second piston, said first compartmeht' having an extended portion located at a spaced distance from the second piston, said casingihaving a longitudinal opening extending fromthe second bore portion to the extended portion of the first com.-

partment, a pressure responsive plunger slidably I mounted in the longitudinal, opening for actuat-- ing the second piston which in turn moves the B5 slidablevalve piston towards itsopen position against the spring means, said plunger having one end extending inthe second bore portionfor engaging the second piston and having its other end subject to the fluid pressure .in the exten-dedportion of the first compartment, and

- a check valve for admittingthe fiow of fluid from the second compartment to the first compartment.

2. A fluid valve comprising, ,in combination, a 7

eparatedzby fatpartition; said partitionthav;

ment I bore. :pass'ing: therethrough and: constitute ing 'gitudinallytiintoithe icasing: uponkopposite fside's of;theiipartitioniandaforming a first bore portion on the first icompartment:iside? of" the partition and raiseconda bore portion on thesecondt-com 1 partment side: ot the i partition,.; as slidable; valve piston? reciprocally mounted in the first bore per-- tiorriandaextending"across the first compartment Q into 1 the bore of ;the partition to regulate the now of fiuid fr'om' ne. compartment vto theother,

ia' second piston slidably mounted' in the second bore portion;.= springmeans for biasing theslidtoxtheitextended' portion ofjthe first compartment, n pressure responsive plungerfslidably mounted in l-thelongitudinal opening for actuating the sec- "ondipistonwhich in' -turn -moves the slidable valve V -pi'sto'n'towards' its open-position against the spring means, said plungerhaving one end extending in the second boregpo'rtion for I engaging the second pistonrand having fits-"other end 1 subj ect to the fluid pressureinthe*extended portionof the first compart'merit,'- a checlr valve for admitting the 'flowgof fiii'id from the second compartment to the first: compartment, and adjustable stop metering 'meansior limiting'zthe movement'of thewslidable vvalve;piston iniits"open'positiona vmfluidvalve comprising, in combinatioma valve casing having a first and a second compartment sepa'rat'ed: bya partition; said partition having a bore passing therethrough and conon the} first compartment side of the partition and asecondbore portion on the second compartmentside of the partition, a slidable valve pis- 1 ton reciprocally mounted, in the first bore portionand extending across the first compartment into the bore of the partition to regulate the flow of fluid from one compartment to the other,

. a second piston slidably mounted in the second boreportion, spring means for biasing the slidable. valve piston toward its closed position into the bore of the partition against the second piston, said first compartment having an extended portion located at a spaced, distance from the second piston, said casing having a longitudinal opening extending from the second bore portion to the extended portion of the first compartment, a pressure responsive plunger slidably mounted in the longitudinal opening for actuating the second piston which in turn moves 1 the slidable valve piston towards its open position against the springmeans, said plunger having oneend extending in the second' bore portion for engaging i the second piston and having its other endsubject to the fluid pressure in the. extended portion of the first compartment, acheckvalve .for admitting the flow of fluid from the second can partment to the first compartment, adjustable stop metering means for limiting the movement of the valve in its openposition and adjustable means for varying the compression of the spring means.

valve :openingazfrom ionefof: isa'idl compart -v mentsl-toithefiothetsaid bore alsoextending. lon't- 4. A fluid valve comprising, in combination, a valve casing having a first and a second compartment separated by a partition, said partition having a bore passing therethrough and constituting a valve opening from one of said compartments to the other, said bore also extending longitudinally into the casing upon oppositetsides of the partition and forming a first bore portion on the first compartment side of the partition and a second bore portion on the second compartment side of th partition, a slidable valve piston reciprocally mounted in the first bore portion and extending across the first compartment into the bore of the partition to regulate the flow of fluid from one compartment to the other, a second piston slidably mounted in the second bore portion, spring means for biasing the slidable valve piston toward its closed position into the bore of the partition against the second piston, said first compartment having an extended portion located at a spaced distance from the second piston, said casing having a longitudinal opening extending from the second bore portion to the extended portion of the first compartment, a pressure responsive plunger slidably mounted in the longitudinal opening for actuating the second piston which in turn moves the slidable valve piston towards its open position against the spring means, said plunger having one end extending in the second bore portion for engaging the second piston and having its other end subject to the fluid pressure in the extended portion of the first compartment, and a check valve for admitting the flow of fluid from the second compartment to the first compartment, said casing having an opening means extending from the outside thereof to the second bore portion in rear of the balancing piston.

5. A fluid valve comprising, in combination, a

valve casing having a first and a. second compartment separated by a partition, said partition having a bore passing therethrough and constituting a valve opening from oneof said compartments to the other, said bore also extending longitudinally into the casing upon opposite sides of the partition and forming a first bore portion on the first compartment side of the partition and a second bore portion on the second compartment side of the partition, a slidable valve piston reciprocally mounted in the first bore portion and extending across the first compartment into the bore of the partition to regulate the flow of fluid from one compartment to the other, a second piston slidably mounted in the second bor-e portion, spring means for biasing the slidable valve piston toward its closed position into the bore of the partition against the second piston, said first compartment having an extended portion located at-a spaced distance from the second piston, said casing having a longitudinal opening extending from the second bore'p'ortion to the extended portion of the first compartment, a pressure responsive plunger slidably mounted in the longitudinal opening for actuating the second piston which in turn moves the slidable valve piston towards its open position against the spring means, said plunger having one end extending in the second bore portion for engaging the second piston and having its other end subject to the fiuid pressure in the extended portion of the first compartment, and a check valve for admitting the flow of fluid from the second compartment to the first compartment, said casing having an opening means extending from the outside thereof to the second bore portion in rear of the balancing piston and to the first bore portion in rear of the slidable valve piston;

PETER L. LOEWE. 

